#include <bits/stdc++.h>
using namespace std;
const int N = 10086;

int a[N], b[N], c[N];
int la, lb, lc;

bool cmp(string& s1, string& s2)
{
	if(s1.size() != s2.size()) return s1.size() < s2.size();
	return s1 < s2;
}

void sub()
{
	for(int i = 0;i < lc;i ++)
	{
		c[i] += a[i] - b[i];
		if(c[i] < 0)
		{
			c[i + 1] -= 1;
			c[i] += 10;
		}
	}
	while(lc > 1 && c[lc - 1] == 0) lc --;
}

int main()
{
	string s1, s2; cin >> s1 >> s2;
	if(cmp(s1, s2))
	{
		cout << "-";
		swap(s1, s2);
	}
	la = s1.size(), lb = s2.size(), lc = max(la, lb);
	for(int i = la - 1;i >= 0;i --) a[la - 1 - i] = s1[i] - '0';
	for(int i = lb - 1;i >= 0;i --) b[lb - 1 - i] = s2[i] - '0';
	sub();
	for(int i = lc - 1;i >= 0;i --) cout << c[i];
	return 0;
}